Algorithms optimization for combined natural gas cooling units control of electric drives taking into account the discreteness of control effect

The problems of main gas pipelines compressor stations electromagnetic compatibility electrical complex of elements, arising when using a frequency-controlled drive of air-cooling devices fans for natural gas, are noted. The feasibility of using combined control systems is substantiated, in which air cooling devices included in the gas cooling unit are divided into two groups: with frequency and discrete regulation of fan speed. The control algorithms optimization issue for electric drives of a combined system by the criterion of power on the fan shaft is discussed. An algorithm for fan speed optimal interconnected control and the number of switched-on fan motors of the air-cooling devices corresponding groups is developed, taking into account the discreteness of the control action. An assessment is given of the power savings on the fan shaft when replacing discrete control with a combined one using the developed control algorithm. It is proposed to use an automatic control system closed by the gas temperature at the outlet of the cooling unit for implementing the optimal algorithm. A comparative the cooling process analysis the energy indicators and the accuracy of temperature maintenance was carried out using the developed optimal control algorithm and an algorithm that does not take into account the discreteness of the control action. It was shown that the use of the latter with a relatively small number of air cooling devices can lead to an unacceptable error in stabilizing the temperature at the outlet of the cooling unit. The control algorithms possibility of using simplified versions is considered. The advantages of using a combined control system, providing a significant energy-saving effect, are shown using the example of a cooling unit containing four two-fan air-cooling devices and operating under conditions of a significantly uneven load.